Highly durable hydrophobic coatings and methods

ABSTRACT

Substrates have a hydrophobic surface coating comprised of the reaction products of a chlorosilyl group containing compound and an alkylsilane. Most preferably the substrate is glass. In one preferred form of the invention, highly durable hydrophobic coatings may be formed by forming a silicon oxide anchor layer or hybrid organo-silicon oxide anchor layer from a humidified reaction product of silicon tetrachloride or trichloromethylsilane, followed by the vapor-deposition of a chloroalkylsilane. Such a silicon oxide anchor layer will advantageously have a root mean square surface roughness of less than about 6.0 nm (preferably less than about 5.0 nm) and a low haze value of less than about 3.0% (preferably less than about 2.0%). Another embodiment of the present invention include the simultaneous humidified vapor deposition of a chlorosilyl group containing compound and a chloroalkylsilane. Specifically, in certain preferred embodiments, the simultaneous vapor deposition onto a glass substrate of silicon tetrachloride (SiCl 4 ) and dimethyldichlorosilane (DMDCS) results in a hydrophobic coating comprised of cross-linked polydimethylsiloxane (PDMSO), which may then be capped with a fluoroalkylsilane (FAS). The cross-linked PDMSO layer may be formed on the surface of the glass substrate, or a silicon oxide anchor layer may be deposited under the cross-linked (PDMSO) layer. SiCl 4  ,trimethylchlorosilane (TMCS), trichloromethylsilane and combinations of these silanes therein may also be simultaneously vapor deposited onto a substrate surface so as to achieve hydrophobic coatings of exceptional durability.

FIELD OF THE INVENTION

[0001] The present invention relates generally to coated substrates andmethods of coating the same. In preferred embodiments, the presentinvention relates to transparent substrates having a hydrophobic (waterrepellant) coating thereon.

BACKGROUND AND SUMMARY OF THE INVENTION

[0002] Glass is typically made of silicates that are melted to form aclear, transparent, solid material. The fundamental molecular structuralunit of conventional glass is a SiO₄ tetrahedron. Ordinary float glass(named for its production process whereby a molten ribbon of glass isfloated on molten metal to provide a smooth surface) includes additionalamounts of soda (Na₂O), usually in the form of sodium carbonate ornitrate during the production process, lime (CaO) and other oxides(usually aluminum and magnesium oxides) to form a soda-lime-silicastructure known colloquially as soda-lime glass. Other specialized glasscan be prepared by the introduction of other additives and constituents.

[0003] It is sometimes highly desirable for conventional glass to havehydrophobic (water repellant) surface properties when employed incertain end-use applications, such as for automotive window glass.Various proposals exist to impart hydrophobic (water-repellant)properties to glass substrates. For example, U.S. Pat. Nos. 4,263,350,4,274,856, 5,665,424 and 5,723,172 (the entire content of each beingincorporated expressly hereinto by reference) disclose generally thatglass surfaces can be coated with a vapor deposited layer of anchloroalkylsilane, such as dimethyldichlorosilane (DMDCS) so as toimprove their hydrophobicity and/or release properties. Other proposalsexist whereby a fluorinated alkylchlorosilane (FAS) coating may beemployed to “cap” an underlayer on a glass substrate so as to improvecoating durability. Please see in this regard, U.S. Pat. Nos. 5,328,768,5,372,851, 5,380,585 and 5,580,605 (the entire content of each beingincorporated expressly hereinto by reference). In addition,International Application WO 00/25938 (the entire content of which isexpressly incorporated hereinto by reference) discloses that a siliconfilm consisting of chains of siloxane groups each terminating in an endmolecule which reacts with water to form an OH group, may be capped byfurther reaction of that OH group with trimethylchlorosilane to formtrimethylsiloxane chain ends.

[0004] While various hydrophobic coatings are known, there is still aneed to provide such coatings with improved durability. It is towardsfulfilling such a need that the present invention is directed.

[0005] Broadly, the present invention is embodied in substrates whichexhibit improved hydrophobicity and durability. Most preferably, thesubstrate is glass. In some of the especially preferred embodiments ofthe present invention, coated substrates and methods are provided whichinclude an SiO_(x)-containing anchor layer comprised of a controllablyhumidified vapor phase deposition of a chlorosilyl group containingcompound (most preferably silicon tetrachloride), and a hydrophobiccapping layer chemically bonded to the SiO_(x)-containing anchor layer.

[0006] In other especially preferred embodiments of the invention,highly durable hydrophobic coatings may be formed by the simultaneousaqueous vapor phase deposition of a chlorosilyl group containingcompound and a chloroalkylsilane to form an anchor layer which may thenbe capped with a hydrophobic coating. For example, the simultaneousvapor deposition onto a glass substrate of silicon tetrachloride anddimethyldichlorosilane results in a hydrophobic coating comprised ofpolysiloxane chains crosslinked with silicon oxide branch points,derived from silicon tetrachloride (i.e. an insoluble reaction product),which may then be capped with a fluoro or chloroalkylsilane. Optionally,a silicon oxide (SiO_(x)) layer may be vapor deposited prior to, andthereby disposed under, the cross-linked polysiloxane in the mannernoted above.

[0007] In other embodiments of the invention, coated substrates on glassmay be produced comprising a first anchor layer comprised of acontrollably humidified vapor phase deposition of a hybridorgano-chlorosilane group containing compound, most preferablymethyltrichlorosilane (MTCS). In other embodiments, various othercombinations of hydrophobic and oleofillic capping layers may bechemically bonded to the hybrid layer.

[0008] These and other aspects and advantages will become more apparentafter careful consideration is given to the following detaileddescription of the preferred exemplary embodiments thereof.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0009] Reference will hereinafter be made to the accompanying drawingswherein like reference numerals throughout the various FIGURES denotelike structural elements, and wherein;

[0010]FIG. 1 is a schematic depiction of a technique to form ahydrophobic coating on a substrate in accordance with one embodiment ofthe present invention;

[0011]FIG. 2 is a schematic depiction of a technique to form ahydrophobic coating on a substrate in accordance with another embodimentof the present invention;

[0012]FIG. 3 is a graph of % Haze vs. % Humidity of a substrate coatedwith a silicon oxide (SiO_(x)) layer; and

[0013] FIGS. 4A-4F schematically depict some exemplary coated glasssubstrates that may be made in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0014] Virtually any substrate that is self-supporting and has, or maybe induced to have active surface hydrogen atoms may be coated inaccordance with the present invention. Thus, rigid or flexiblesubstrates formed of glass, plastics, ceramics, and the like may becoated in accordance with the present invention. Most preferably, thesubstrate is glass, with conventional soda-lime float glass beingespecially preferred.

[0015] In one particularly preferred coating in accordance with thepresent invention, an anchor layer comprised of a silicon oxide(SiO_(x)) is formed by vapor-deposition of a silicon-oxide formingcompound onto the substrate in a controllably humidified environment. Inespecially preferred forms of the invention, the silicon oxide layer maybe obtained by the reaction of a compound having a chlorosilyl group,such as silicon tetrachloride (SiCl₄). In other forms of the invention,the anchor layer may be obtained by the humidified reaction of anorgano-chlorosilyl group to yield a hybrid organo-silicon oxide layer.The organo-chlorosilyl group may be a trichloroalkyl- or trichloroarylsilane such at methyltrichlorosilane (MTCS) or trichlorophenylsilane(TCPS).The compounds are reacted with the surface of the glass so as toform an underlayer containing SiO_(x) or hybrid SiO_(x)R_(y) groupswhere R is an organic group having six or less carbon atoms. Othersilanes that form silicon oxide, or oxidic-like materials, mayoptionally, or additionally, be employed. For example, compounds such ashexachlorodisiloxane, trichloroalkylsilane wherein the alkyl groupcomprises one to six carbons and may be linear, cyclic, or branched oran aromatic group of up to six carbons can be employed. When usingsilicon tetrachloride, it has been found that diluting 1 part thesilicon tetrachloride with 10 parts pentane is particularly effective inpreparing useful coatings.

[0016] Accompanying FIG. 1 depicts schematically a particularlypreferred technique for forming a hydrophobic coating in accordance withthe present invention. In this regard, in one hydrophobic coatingpreparation, vapor-phase silicon tetrachloride is introduced into aclosed chamber having a controlled interior humidity environment whichresults in silicon oxide units attaching directly to the glass substratesurface. Rehydrating the chlorine-terminated silicon oxide units (e.g.,by controlling the humidity in the reaction chamber) results inreplacing terminal chlorine atoms with hydroxyl groups so that, upon theadditional sequential introduction of vapor-phase chloroalkylsilanessuch as dimethyldichlorosilane (DMDCS), trimethylchlorosilane (TMCS),and methyltrichlorosilane (MTCS), and the like, with intermediaterehumidification of the chamber, durable hydrophobic coatings ofpolydimethylsiloxane (PDMSO), or other polysiloxane are obtained.Preferred silanes that may be used in accordance with the presentinvention are represented by the formula Cl_(x)SiR_(y), where x is atleast 1 4, and y is at least 1, R is an alkyl or aryl group which mayalso be a oleophillic group, e.g. a fluorinated alkyl.

[0017] The humidity during vapor-phase deposition of the silicon oxideanchor layer is important to achieve the desired end result of a durablehydrophobic coating on the substrate. In addition, controlled humidityduring vapor phase deposition of the silicon oxide layer is important toachieve a coating with low haze characteristics. Thus, as generallyillustrated in accompanying FIG. 2, the humidity during vapor phasedeposition of the silicon oxide anchor layer from silicon tetrachlorideshould be less than about 50% relative humidity, and advantageously lessthan about 45% relative. Preferably the relative humidity within thechamber is controlled to be about 40% or less. Thus, the silicon oxideor hybrid organo-silicon oxide layer will most preferably exhibit haze(non-specular light scattering) of less than about 3.0%, and typicallyless than about 2.0%. Advantageously, the haze of the silicon oxidelayer will be less than about 1.5%, particularly less than about 0.8%.

[0018] The lower limit of relative humidity, and hence haze value, ofthe silicon oxide anchor layer is believed to be determined by thesurface roughness that is desired. In this regard, it has been foundthat the greater the humidity, the greater the surface roughness of theresulting silicon oxide anchor layer and vice versa. Without wishing tobe bound to any particular theory, it is believed that the surfaceroughness of the silicon oxide layer contributes materially to thedurability of the hydrophobic coatings obtained according to theinvention as the peaks and valleys of the “rough” anchor layer providesphysical pockets of various sizes and shapes where the later appliedchloroalkylsilane can be deposited. In addition, a “rough” anchor layerof silicon oxide or hybrid organo-silicon oxide may provide an increasedsurface area resulting in the chloroalkylsilane being more dense perunit area on the substrate thereby possibly improving durabilityproperties of the resulting coating.

[0019] In accordance with the present invention, therefore, it has beenfound that the silicon oxide or hybrid organo-silicon oxide anchor layerpreferably has a root mean square (RMS) surface roughness of less thanabout 6.0 nm, and preferably less than about 5.0 nm. The RMS surfaceroughness of the silicon oxide layer preferably, however, is greaterthan about 4.0 nm. Therefore, the RMS surface roughness of the siliconoxide layer is advantageously between about 4.0 nm to about 6.0 nm, andmore preferably between about 4.0 nm to about 5.0 nm. Too great a RMSsurface area is disadvantageous since relatively large surface peaks,widely spaced apart, begin to diminish the desirable increased surfacearea. On the other hand, too small a RMS surface results in the surfacebeing too smooth, that is to say an insufficient increase in the surfacearea and/or insufficient depth of the surface peaks and valleys on thesurface.

[0020] As used herein and in the accompanying claims, the “root meansurface area”, and “RMS surface area” and like terms are meant to referto a measure of surface deviation from a flat, smooth surface asdetermined by atomic force microscope (AFM).

[0021] The PDMSO layer may optionally be overcoated (or capped) with analkyl silane capping layer. In this regard, virtually any suitable alkylsilane may be employed to form a capping layer in accordance with thepresent invention, such as those described in the above-cited U.S. Pat.Nos. 5,328,768, 5,372,851, 5,380,585 and 5,580,605. For example, thecapping layer may be formed by the vapor phase deposition of at leastone fluoroalkylchlorosilane selected from the group consisting ofCF₃(CF₂)₅(CH₂)₂SiCl(CH₃)₂,and(CF₃)₂FC-O(CH₂)₃SiCl₂CH₃.

[0022] Another particularly preferred embodiment of the presentinvention involves the simultaneous vapor deposition of a compoundcontaining a chlorosilyl group and an alkylchlorosilane compound, toachieve essentially cross-linked PMDSO. This cross-linked PMDSO layermay be formed directly on the surface of the substrate, or may be formedon a previously applied silicon oxide or hybrid organo-silicon oxideanchor layer as described previously. The cross-linked PMDSO layer ismost preferably capped with one or more layers formed by the individualvapor-deposition of alkylchlorosilanes and/or alkylchlorofluorosilane(i.e. “alkylfluorosilane”) compounds. For example, especially desirablehydrophobicity and durability properties have been achieved by thesimultaneous vapor deposition of silicon tetrachloride and DMDCS toobtain an underlayer on the substrate, which is thereafter capped with alayer of an alkylfluorosilane compound. Most preferably, the volumeratio of the simultaneously vapor-deposited chlorosilyl compound and thealkylchlorosilane compound will be between about 1:1 to about 1:30, andmore preferably between about 1:5 to about 1:15. An especially preferredratio (particularly when simultaneously vapor-depositing silicontetrachloride and DMDCS) is about 1:10.

[0023] According to another specific embodiment in accordance with thepresent invention, silicon tetrachloride (SiCl₄) andtrimethylchlorosilane (TMCS) or methyltrichlorosilane (MTCS) aresimultaneously vapor deposited onto a glass surface to achieve a usefulhydrophobic coating. Most preferably the SiCl₄ and TMCS are vapordeposited as a mixture having a ratio of SiCl₄ to TMCS within the rangeof between about 4.0:0.5 to about 4.0:1.5, and more preferably about4.0:1.0 (for example, between about 4.0:0.9 to about 4.0:1.1). Asbriefly noted above, alkylchlorosilanes other than TMCS may be employedin admixture with SiCl₄, for example, dimethyldichlorosilane andmethyltrichlorosilane. In addition, layers formed by the simultaneousvapor deposition of SiCl₄ and an alkylchlorosilane may be capped, ifdesired, in a manner described above with an alkylchlorosilane. In thisregard, when SiCl₄ and TMCS are simultaneously vapor deposited, asuitable capping layer may be a vapor deposited layer oftriethylchlorosilane (TECS) (i.e., so as to form a cap layer comprisedof triethyl silane).

[0024] Accompanying FIG. 2 shows schematically one preferred techniquefor forming a cross-linked PMDSO layer in accordance with the presentinvention. In this regard, silicon tetrachloride and DMDCS arevapor-deposited simultaneously in a closed humidity-controlled chamberto form a cross-linked PMDSO layer on the glass substrate. Thereafter,the chamber may be rehumidified and supplied with a vapor of TMCS whichserves to cap the cross-linked PMDSO layer.

[0025] FIGS. 4A-4F depict a few exemplary coated glass substrates thatmay be made in accordance with the present invention. In this regard,for ease of understanding, each of the layers depicted in FIGS. 4A-4Frefer to the precursor vapors, and not to the reaction products of suchvapors. It will also be understood that, before another compound isvapor-deposited, the chamber is rehumidified as may be needed. Thus, forexample, as viewed outwardly from the surface of the glass substrate,accompanying FIG. 4A shows a vapor-deposited layer of silicontetrachloride as an anchor layer, followed by sequential vapor-depositedlayers of DMDCS and TMCS. FIG. 4B depicts an underlayer comprised ofsimultaneously vapor-deposited silicon tetrachloride and DMDCS, followedby a separately vapor-deposited TMCS layer. FIG. 4C is similar to thecoating of FIG. 4B, but includes a capping layer of afluoroalkylchlorosilane (FAS). FIG. 4D is similar to FIG. 4A, butincludes a layer of simultaneously vapor-deposited silicon tetrachlorideand DMDCS interposed between the vapor-deposited silicon tetrachlorideanchor layer and the vapor-deposited TMCS layer. FIG. 4E is similar toFIG. 4D, but includes sequentially vapor-deposited layers of DMDCS andTMCS over the simultaneously vapor-deposited layer of silicontetrachloride and DMDCS. FIG. 4F is similar to FIG. 4D but includes ahydrophobic layer formed by the simultaneous vapor deposition of silicontetrachloride and TMCS. An optional capping layer is also shown in FIG.4F as being a vapor deposited layer of triethylchlorosilane (TECS), butmay such a capping layer may be omitted if desired.

[0026] In other preferred embodiments, the substrate can have a firsthydrophobic surface coating of a vapor deposited hybrid organo-siliconmaterial which will produce a hydrophobic surface of a hybridorgano-silicon oxide layer such as that derived from trichloromethylsilane. In still other preferred embodiments having a hybrid firsthydrophobic surface coating, additional vapor deposited layers ofsilicon tetrachloride, dimethyidichlorosilane and chlorotrimethylsilaneor their mixtures may be used. When mixtures of these materials are usedto prepare vapor deposited surface coatings the ratios of the variouscomponents can be varied. For example, the ratios of binary and ternarymixtures of silanes may range from equimolar amounts added to thereactor to fractions of each, depending on the properties desired.

[0027] The thickness of the various layers obtained according to thepresent invention are not especially critical, provided the desiredhydrophobicity and/or durability properties are achieved. Thus, layerthickness in the range of between about 10 to about 10,000 Angstroms,and typically between about 20 to about 5000 Angstroms may be provided.

[0028] The coated substrates of the present invention will exhibit atilt angle (30 μL droplet size) of about 35° or less, and typically 30°or less. For some embodiments of the present invention, extremely lowtilt angles of about 20° or less, or even about 10° or less, areobtainable. The coatings of the present invention are also highlydurable. That is, the coated substrates of the present invention willexhibit a contact angle after 300 Taber abrasion cycles of greater thanabout 65°,and typically greater than about 70°. Even after 1000 Tabercycles, the coated substrates of the present invention will exhibit acontact angle of greater than about 60°, usually between (or from) about65° to about 75°.

[0029] The coated substrates of the present invention can beconveniently produced using a closed reaction chamber configured to havean inlet opening for the chemical vapors, and a discharge opening toallow the chamber to be exhausted. The substrates are cleaned thoroughlyand rinsed prior to being placed in the reaction chamber. The humiditywithin the chamber is controlled by the introduction of water vapor independence upon the chemical vapors being deposited. Thus, humiditywithin the reaction chamber of greater than about 10%, and less thanabout 80% are typically employed. The reaction chamber is mostpreferably maintained under ambient temperature (20° C.-25° C.) andatmospheric pressure (about 1.0 atmosphere) conditions during the vapordeposition of the underlayer and capping layer(s).

[0030] The present invention will be further understood by reference tothe following non-limiting Examples.

EXAMPLES

[0031] Substrates used for evaluation in the following examples wereclear annealed 3 mm float glass. Only coating applied to the air side ofthe substrate was evaluated. The substrates were coated in apolypropylene reaction chamber having the dimensions of approximately16″ L×14″ W×8″ D. The chamber included a glass lid to allow for visualprocess observations. Dry air, humid air, or dry air saturated withcoating precursor vapor was introduced at one end of the chamber, andexhausted at the other.

[0032] The glass substrates were cleaned and then placed into thereaction chamber, aligned parallel to the gas flow. Humid air wasproduced by bubbling air through water kept at a substantially constanttemperature of 40° C. The humidity level in the chamber was maintainedsubstantially constant by admixing dry air. Reaction precursors wereintroduced in a similar manner, that is, by flowing dry air over theprecursor liquid and into the chamber. After each process step wascompleted, unreacted vapors were exhausted from reaction chamber for aminimum of 5 minutes prior to removal of the coated substrates.

[0033] Some of the substrates evaluated were additionally surfacetreated, by applying liquid chlorofluoroalkylsilane (FAS) onto thesurface. The FAS compounds were identified as FAS(A) having the formulaCF₃(CF₂)₅(CH₂)2SiCl(CH₃)₂ and FAS(B) having the formula(CF₃)₂FC-O(CH₂)₃SiCl₂CH₃.

[0034] Unreacted material was removed by cleaning the surface withn-butanol, followed by hand buffing with a clean cloth or paper towel.

[0035] The substrates were evaluated using the following test methodsand techniques:

[0036] Contact Angle: Advancing contact angle was measured at variouslocations on the coated substrate. The recorded value represented theaverage value of all measured readings.

[0037] Abrasion Resistance: The abrasion resistance was evaluated on thebasis of contact angle change at the abrasion location. The coating wasTaber-abraded using CS-10F wheels and 500 g load. The CF-10F wheels wereresurfaced prior to each abrasion test (25 cycles with resurfacingstone). After 300 cycles, the substrate was removed from abrader andcleaned. The Taber track was cleaned by immersing the substrate in warmdistilled water (40-45C.) for 5-10 seconds. The Taber track was wipedwith clean Preference brand paper towels. The substrate was thereafterrinsed with room temperature distilled water. The surface to be testedwas dried with compressed air. After the contact angle measurement, thesubstrate was abraded for an additional 700 cycles. The substrates werecleaned as before and the contact angle was again measured.

[0038] Tilt Angle: The coated substrate was placed on an instrument thatwas able to tilt and record the angle of such tilt. A 30 micro literdrop of distilled water was gently placed on the surface to be tested atan initial tilt angle of 0 degrees. The angle at which the surface wastilted was increased periodically at 1° increments until the drop ofwater flowed across the surface. The angle of the surface at that timewas then recorded as the tilt angle.

Example I (Comparative)

[0039] A glass substrate was cleaned using the following procedure: Thesubstrate was first rinsed off with tap water. BON AMI™ cleaner wasplaced on a wet sponge and the surface was cleaned with the sponge usingapproximately 3 to 5 pounds of pressure, following which the substratewas again rinsed with tap water. LIQUINOX™ soap which had been reducedone part soap to 100 parts distilled water was applied to wet surface.The surface was cleaned with the soap and a soft brush also at 3 to 5pounds of pressure. After an appropriate amount of cleaning, the surfacewas rinsed first with tap water and then with distilled water. Thewetting of the substrate surface after cleaning was used to determinethe cleanliness of the glass surface. The substrate was placed into acarrier and blown dry using dried compressed air.

[0040] The cleaned substrate was then placed into the reaction chamberparallel to the gas flow. The reaction chamber humidity was adjusted to78%, and then held at that humidity for 5 minutes. After a stabilizationperiod of 30 seconds, dimethyidichlorosilane (DMDCS) was introduced intoreaction chamber for an additional 5 minutes. After an additional30-second stabilization period, the gases were exhausted from thechamber for 10 minutes, following which the substrate was removed fromthe chamber. Excess material was the removed with N-butanol and thesurface was buffed with clean paper towel.

Example II (Comparative)

[0041] A glass substrate was cleaned per Example I. The substrate wasplaced into a carrier and blown dry using dried compress air. Thecleaned substrate was placed into the reaction chamber parallel to thegas flow. Chamber humidity was adjusted to 78%, and then held at thatelevated humidity for 5 minutes. After a stabilization period of 30seconds, dimethyldichlorosilane (DMDCS) was introduced into the reactionchamber for an additional 5 minutes. The chamber was thereafter purged,and after a second stabilization period, the reaction chamber wasadjusted to 81%. The humidity was held for 5 minutes and the substratewas then removed from the chamber. Immediately after removal from thechamber a thin layer of FAS (A) was applied by hand to the substrateover the excess silane using a paper towel. The substrate was allowed tostand for 30 to 90 seconds. The excess material was then removed withN-butanol, and the surface was buffed with a clean paper towel.

Example III (Comparative)

[0042] A glass substrate was cleaned per Example I. The substrate wasplaced into a carrier and blown dry using dried compress air. Thecleaned substrate was placed into the reaction chamber parallel to thegas flow. Chamber humidity was adjusted to 14%, and then held at thathumidity for 5 minutes. After a stabilization period of 30 seconds,silicon tetrachloride was introduced into the reaction chamber for anadditional 5 minutes. The chamber was thereafter purged, and after asecond stabilization period, the reaction chamber was adjusted to 80%.The humidity was held for 5 minutes, following which the substrate wasremoved from the chamber. Immediately after removal from chamber a thinlayer of FAS (A) was applied by hand to the substrate over the excesssilane using a paper towel. The substrate was allowed to stand for 30 to90 seconds. The excess material was then removed with N-butanol, and thesurface was buffed with clean paper towel.

Example IV (Invention)

[0043] A glass substrate was cleaned using the following procedure.WINDEX™ cleaner with ammonia was applied to the surface of both sides.The wet surface was scrubbed with paper towel. The substrate was thenpolished with a clean paper towel, removing all excess cleaner. Thecleaned substrate was then placed into the reaction chamber parallel tothe gas flow. The chamber humidity was adjusted to 14%, and then heldthere for 5 minutes. After a stabilization period of 30 seconds, silicontetrachloride was introduced into the reaction chamber for an additional5 minutes. The chamber was thereafter purged, and after a secondstabilization period, the reaction chamber was rehumidified to 38%.After yet another 30-second stabilization period, dimethyldichlorosilane(DMDCS) was added to chamber for a total of 5 minutes. After a final30-second stabilization period, the gases were exhausted from thechamber for 10 minutes, following which the substrate was removedtherefrom. Excess material was then removed with N-butanol, and thesurface was buffed with clean paper towel.

Example V (Invention)

[0044] A glass substrate was clean using the following procedure. Thesubstrate was rinsed with tap water. LIQUINOX™ soap which had beenreduced one part soap to 100 parts distilled water was applied to thewet surface and the surface cleaned with the soap and a soft brush at 3to 5 pounds of pressure. After an appropriate amount of cleaning, thesurface was rinsed first with tap water and then with distilled water.The wetting of the substrate surface after cleaning was used todetermine the cleanliness of the glass surface. The substrate was placedinto a carrier and blown dry using dried compress air. The cleanedsubstrate was placed into the reaction chamber parallel to the gas flow.Chamber humidity was adjusted to 14%, and then held at that humidity for5 minutes. After a stabilization period of 30 seconds, a mixture of 5parts dimethyldichlorosilane (DMDCS) and one part silicon tetrachloridewas introduced into the reaction chamber for 5 minutes. After anadditional 30-second stabilization period, the gases were exhausted fromthe chamber for 10 minutes, following which the substrate was removedfrom the chamber. FAS(B) was added and after 60-90 seconds, the glasssubstrate was cleaned with N-butanol.

Example VI (Invention)

[0045] A glass substrate was cleaned per Example I. The cleanedsubstrate was placed into the reaction chamber parallel to the gas flow.Chamber humidity was adjusted to 14%, and then held at that humidity for5 minutes. After a stabilization period of 30 seconds, silicontetrachloride was introduced into the reaction chamber for an additional5 minutes. The chamber was thereafter purged, and after a secondstabilization period, the reaction chamber was rehumidified to 14% andheld for 5 minutes. After a 30-second stabilization period, a mixture of5 parts dimethyldichlorosilane and one part silicon tetrachloride wasintroduced into reaction chamber for 5 minutes. The chamber was againpurged and allowed to stabilize for 30 additional seconds, and thechamber humidity was adjusted to 77%. After 5 minutes at 77% humidity,the substrate was removed from the chamber. Immediately after removalfrom chamber, a thin layer of FAS (A) was applied by hand to thesubstrate over the excess silane using a paper towel. The substrate wasallowed to stand for 30 to 90 seconds. The excess material was thenremoved with N-butanol, and the surface was buffed with clean papertowel.

Example VII (Invention)

[0046] A glass substrate was cleaned per Example I. The cleanedsubstrate was placed into the reaction chamber parallel to the gas flow.The chamber humidity was adjusted to 14%, and then held at that humidityfor 5 minutes. After a stabilization period of 30 seconds, silicontetrachloride was introduced into reaction chamber for an additional 5minutes. The chamber was thereafter purged, and after a stabilizationperiod of about 30 seconds, the reaction chamber was rehumidified to14%. and held there for 5 minutes. After another 30-second stabilizationperiod, a mixture of 5 parts dimethyldichlorosilane and one part silicontetrachloride, was introduced into the reaction chamber for 5 minutes.The chamber was vented and rehumidified to 59% and held for 5 minutes,following which DMDCS vapor was introduced for 5 minutes. The chamberwas thereafter vented and was again allowed to stabilize for 30 seconds,and the chamber humidity was adjusted to 77%. After 5 minutes at 77%humidity, the substrate was removed from the chamber. Immediately afterremoval from chamber, a thin layer of FAS(B) was applied by hand to thesubstrate over the excess silane using a paper towel. The substrate wasallowed to stand for 30 to 90 seconds. The excess material was thenremoved with N-butanol, and the surface was buffed with clean papertowel.

[0047] The coated float glass substrates of Examples I through VII wereexamined for abrasion resistance and tilt angle. The data appears inTable A below. TABLE A Example Contact Angle After Taber Cycles TiltAngle No. 0 300 1000 (30 μl Drop) I 101⁰ 56⁰ 43⁰ 26⁰ II 117⁰ 52⁰ 43⁰ 33⁰III 106⁰ 50⁰ 45⁰ 24⁰ IV 100⁰ 70⁰ 67⁰ 27⁰ V 107⁰ 74⁰ 66⁰ 33⁰ VI 108⁰ 74⁰67⁰ 19⁰ VII  98⁰ 84⁰ 67⁰ 10⁰

[0048] As can b seen from the data above, a comparison of Examples I andIV reveals that improved durability ensues with an initial vapordeposited silica layer following by a vapor deposited DMDCS top layerrelative to a DMDCS layer only. Furthermore, the simultaneous vapordeposition of DMDCS SiCl₄ (leading to a crosslinked polydimethylsilxanePDMSO) underlayer) which is capped with a liquid applied FAS layerresults in improved durability relative to a vapor deposited DMDCS layeronly. (Compare, Examples V and I.) The data of Example VI and VII revealthat the simultaneous vapor deposition of DMDCS and SiCl₄ which iscapped with liquid applied FAS results in surprisingly lower tiltangles.

Examples VIII and IX (Comparative)

[0049] Examples I and II were repeated, respectively, except that inExample IX, TMCS was employed instead of FAS(A) as a capping layer. Theresults of Taber abrasion and tilt angle testing appear in Table Bbelow.

Example X (Invention)

[0050] A glass substrate was coated in a closed chamber into which vaporphase precursor compounds were introduced. Specifically, the followingformulation was employed in the sequence noted below to obtain a coatedglass substrate having the structure depicted in FIG. 4A. The chamberwas allowed to stabilize for about 5 minutes following introduction ofeach vapor compound. In addition, the chamber was purged by vacuumbefore each new vapor was introduced so that the humidity within thechamber could be adjusted as noted.

[0051] (1) 20% RH, SiCl₄ in pentane

[0052] (2) 60% RH, DMDCS

[0053] (3) 60% RH, TMCS

[0054] The results of Taber abrasion and tilt angle testing appear inTable B below.

Example XI (Invention)

[0055] Example X was repeated using the following formulation sequenceto achieve a coated glass substrate generally depicted in FIG. 4B:

[0056] (1) 40% RH, simultaneous DMDCS and SiCl₄

[0057] (2) 60% RH, TMCS

[0058] The results of Taber abrasion and tilt angle testing appear inTable B below.

Example XII (Invention)

[0059] Example XI was repeated except that FAS(A) was wiped on by handinstead of using vapor-deposited TMCS to achieve a coated glasssubstrate generally depicted in FIG. 4C. The results of Taber abrasionand tilt angle testing appear in Table B below.

Example XIII (Invention)

[0060] Example X was repeated using the following formulation sequenceto achieve a coated glass substrate generally depicted in FIG. 4D:

[0061] (1) 20% RH, SiCl₄ in pentane

[0062] (2) 40% RH, simultaneous DMDCS and SiCl₄

[0063] (3) 60% RH, TMCS

[0064] The results of Taber abrasion and tilt angle testing appear inTable B below.

Example XIV (Invention)

[0065] Example X was repeated using the following formulation sequenceto achieve a coated glass substrate generally depicted in FIG. 4E:

[0066] (1) 20% RH, SiCl₄ in pentane

[0067] (2) 40% RH, simultaneous DMDCS and SiCl₄

[0068] (3) 60% RH, DMDCS

[0069] (4) 60% RH, TMCS

[0070] The results of Taber abrasion and tilt angle testing appear inTable B below. TABLE B Example Contact Angle After Taber Cycles TiltAngle No. 0 300 1000 (30 μl Drop) VIII 115⁰ 54⁰ 46⁰ 38⁰ IX 118⁰ 61⁰ 55⁰28⁰ X 106⁰ 91⁰ 74⁰ 10⁰ XI 117⁰ 71⁰ 68⁰ 29⁰ XII 118⁰ 70⁰ 69⁰ 10⁰ XIII120⁰ 71⁰ 74⁰ 40⁰ XIV 107⁰ 86⁰ 75⁰ 12⁰

[0071] The data in Table B also reveal that improved hydrophobicity anddurability ensue with the coatings in accordance with the presentinvention.

Example XV (Invention)

[0072] Green automotive window glass comprised of a layer of 0.76 mmthick PVB film laminated between a pair of 2.1 mm thick glass layers wascoated in the same manner as Example X using 20% RH in the chamber and amixture of SiCl₄ and TMCS at a ratio of 4:1, respectively, using pentaneas a carrier. Specifically, a mixture of 100 ml pentane, 5 ml SiCl₄ and1.25 ml TMCS were employed for purpose of vapor deposition onto a toplayer of the automotive glass laminate. The resulting coated glasssubstrate was found to have optical characteristics of about 79.9%Transmission and about 0.24% Haze, and color characteristics of L*=90.8,a*=−6.8 and b*=1.6. The coated glass substrate was subjected to Taberwear and tilt angle tests with the results being reported below in TableC. TABLE C Contact Angle After Taber Cycles Tilt Angle 0 300 1000 20003000 4000 (10 μl Drop) (30 μl Drop) 88.8⁰ 78.1⁰ 70.1⁰ 68.5⁰ 67.0⁰ 64.5⁰40⁰ 38⁰

[0073] As the data in Table C demonstrate, the coating is opticallysatisfactory and exhibits extremely durable hydrophobicity (as evidencedby the contact angle data after many thousands of Table cycles).

Example XVI (Invention)

[0074] Green auto glass was prepared as in Example XV(Invention) with anadditional layer of a vapor deposited mixture of DMDCS and SiCl₄ andsequentially added layers of DMDCS and TMCS respectively. The ContactAngles After Taber Cycles and Tilt Angle are listed in Table D, below.TABLE D Contact Angle After Taber Cycles Tilt Angle 0 300 1000 2000 30004000 (10 μl Drop) (30 μl Drop) 107° 83.2° 76.9⁰ 72.5⁰ 70.4⁰ 68.3⁰ 18⁰13⁰

Example XVI (Invention)

[0075] A glass substrate is cleaned by first rinsing with tap water andLIQUINOX™ soap that is reduced to one part soap to 100 parts distilledwater. The solution is applied to the wet substrate surface and cleanedwith a soft brush using 3 to 5 pounds of pressure. The surface is rinsedfirst with tap water and then with distilled water. The substratesurface is deemed clean when distilled water rinses clear. The cleanedsubstrate is placed into a carrier and blown dry using dried compressair. The cleaned substrate is placed into the reaction chamber parallelto the gas flow. After a period to ensure stabilization of the humiditywithin the reaction chamber, about 30 seconds, silicon tetrachloride(SiCl₄) is introduced into the reaction chamber for about 5 minutes togenerate a first layer of Silicon Oxide, SiO_(x) layer having an RMSsurface roughness of at least 4 μ and preferably less than about 6 mμ.The chamber is subsequently purged, and rehumidified to at least about14 percent. After a 30-second stabilization period,dimethyldichlorosilane (DMDCS- SiCl₂Me₂) and methyltrichlorosilane(MTCS) are added in equivolume (one part to one part) amounts to thechamber for a total of 5 minutes. The reaction chamber humidity isadjusted to about 14%, and then held at a relatively constant humidityfor about 5 minutes to then generate a crosslinked layer. The initialadvancing contact angle is greater than 60° and greater than 45° after300 Taber Cycles.

Example XVII (Invention)

[0076] A glass substrate is cleaned using the procedure in Example XVI.The cleaned substrate is placed into a carrier and blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. After a period to ensure stabilization of thehumidity within the reaction chamber, about 30 seconds, silicontetrachloride (SiCl₄) is introduced into the reaction chamber for about5 minutes to generate a first Silicon Oxide layer, SiO_(x), having anRMS surface roughness of at least 4 mμ and preferably less than about 6mμ. The chamber is purged, and rehumidified to at least about 14percent. After a 30-second stabilization period, dimethyldichlorosilane(DMDCS-SiCl₂Me₂) and methyltrichlorosilane are added to the chamber fora total of 5 minutes in ratios of DMDCS to MTCS of about 9 parts to 1parts. The reaction chamber humidity is adjusted to about 14%, and heldat a relatively constant humidity for about 5 minutes to then generate acrosslinked layer. The reaction chamber is subsequently evacuated andthe coated substrate is removed from the chamber. The initial advancingcontact angle is greater than 70° and greater than 55° after 300 TaberCycles.

Example XVIII (Invention)

[0077] A glass substrate is cleaned using the procedure in Example XVI.The cleaned substrate is placed into a carrier and blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. After a period to ensure stabilization of thehumidity within the reaction chamber, about 30 seconds, silicontetrachloride (SiCl₄) is introduced into the reaction chamber for about5 minutes to generate a first layer of Silicon Oxide, SiO_(x), having anRMS surface roughness of at least 4 nm and preferably less than about 6mn. The chamber is subsequently purged, and rehumidified to at leastabout 14 percent. After a 30-second stabilization period,dimethyidichlorosilane (DMDCS- SiCl₂Me₂) and methyltrichlorosilane(MTCS-SiCl₃CH₃) are added to the chamber for a total of 5 minutes inratios of DMDCS to MTCS of about 3 part to 1 parts by weight. Thereaction chamber humidity is adjusted to about 14%, and then held at arelatively constant humidity for about 5 minutes to then generate acrosslinked layer. The reaction chamber is subsequently evacuated aftera final coating is applied, and the coated substrate is removed from thechamber. The initial advancing contact angle is greater than 70° andgreater than 55° after 300 Taber Cycles.

Example XIX (Invention)

[0078] A glass substrate is cleaned using the procedure in Example XVI.The cleaned substrate is placed into a carrier and blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. After a period to ensure stabilization of thehumidity within the reaction chamber, about 30 seconds, silicontetrachloride (SiCl₄) is introduced into the reaction chamber for about5 minutes to generate a first layer of SiO_(x) having an RMS surfaceroughness of at least 4 nm and preferably less than about 6 nm. Thechamber is subsequently purged, and rehumidified to at least about 14percent. After a 30-second stabilization period, dimethyldichlorosilane(DMDCS- SiCl₂Me₂) and methyltrichlorosilane (MTCS-SiCl₃CH₃) are added tothe chamber for a total of 5 minutes in ratios of DMDCS to MTCS of about1 to 3 parts by weight. The reaction chamber humidity is adjusted toabout 14%, and then held at a relatively constant humidity for about 5minutes to then generate a crosslinked layer. After an additionalstabilization period of at least 30 seconds, additionalmethyltrichlorosilane (DMDCS) is introduced into the reaction chamberfor an additional five minutes to provide a final capping layer. Thereaction chamber is subsequently evacuated after a final coating isapplied, and the coated substrate is removed from the chamber. Theinitial advancing contact angle is greater than 105° and greater than65° after 300 Taber Cycles.

Example XX (Invention)

[0079] A glass substrate is cleaned using the procedure in Example XVI.The cleaned substrate is placed into the reaction chamber parallel tothe gas flow. After a period to ensure the stabilization of the humiditywithin the reaction chamber, about 30 seconds, silicon tetrachloride(SiCl₄) is introduced into the reaction chamber for about 5 minutes togenerate a first layer having an RMS surface roughness of at least 4 mμand preferably less than about 6 mμ. The chamber is subsequently purged,and rehumidified to at least about 14 percent. After a 30-secondstabilization period, dimethyidichlorosilane (DMDCS- SiCl₂Me₂) andmethyltrichlorosilane (MTCS- SiCl₃CH₃), and Silicon Tetrachloride(SiCl4) are added in equimolar amounts to the chamber for a total of 5minutes. The reaction chamber humidity is adjusted to about 14%, andthen held at a relatively constant humidity for about 5 minutes. Thereaction chamber is evacuated after a final coating is applied,following which the coated substrate is removed from the chamber. Theinitial advancing contact angle is greater than 60° and greater than 45°after 300 Taber Cycles.

Example XXI (Invention)

[0080] A glass substrate is cleaned using the procedure in Example XVI.The cleaned substrate is placed into the reaction chamber parallel tothe gas flow. After a period to ensure the stabilization of the humiditywithin the reaction chamber, about 30 seconds, silicon tetrachloride(SiCl₄) is introduced into the reaction chamber for about 5 minutes togenerate a first layer having an RMS surface roughness of at least 4 mμand preferably less than about 6 mμ. The chamber is subsequently purged,and rehumidified to at least about 14 percent. After a 30-secondstabilization period, dimethyidichlorosilane (DMDCS- SiCl₂Me₂) andmethyltrichlorosilane (MTCS-SiCl₃CH₃), and Silicon Tetrachloride (SiCl4)are added in equimolar amounts to the chamber for a total of 5 minutes.The reaction chamber humidity is adjusted to about 14%, and then held ata relatively constant humidity for about 5 minutes. After an additionalstabilization period of at least 30 seconds, to ensure humidity iscorrect and stable, additional methyltrichlorosilane is introduced intothe reaction chamber for an additional five minutes to provide a cappinglayer. The reaction chamber is evacuated after a final coating isapplied, following which the coated substrate is removed from thechamber. The initial advancing contact angle is greater than 60° andgreater than 45° after 300 Taber Cycles.

Example XXII (Invention)

[0081] A glass substrate is cleaned using the procedure in Example XVI.The substrate is placed into a carrier and blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. After a period to ensure the stabilization ofthe humidity within the reaction chamber, about 30 seconds, silicontetrachloride (SiCl₄) is introduced into the reaction chamber for about5 minutes to generate a first layer having an RMS surface roughness ofat least 4 mμ and preferably less than about 6 mμ. The chamber issubsequently purged, and rehumidified to at least about 14 percent.After a 30-second stabilization period, dimethyidichlorosilane (DMDCS-SiCl₂Me₂) and methyltrichlorosilane (MTCS-SiCl₃CH₃), and SiliconTetrachloride (SiCl₄) are added to the reaction chamber with thequantities of each reactant being a ratio of 1 parts DMDCS, 1 parts MTCSand 2 parts of SiCl₄ by weight added to the reaction chamber for a totalof 5 minutes. The reaction chamber humidity is adjusted to about 14%,and held at a relatively constant humidity for about 5 minutes. After anadditional stabilization period of at least 30 seconds to stabilize thehumidity level methyltrichlorosilane is introduced into the reactionchamber for an additional five minutes to provide a capping layer. Thereaction chamber is evacuated after the final coating is applied and thesubstrate is removed from the chamber. The initial advancing contactangle is greater than 60° and greater than 45° after 300 Taber Cycles.

Example XXIII (Invention)

[0082] A glass substrate is cleaned using the procedure in Example XVI.The substrate is placed into a carrier and is blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. Chamber humidity is adjusted to 14%, and thenheld at that humidity for 5 minutes. After a stabilization period of 30seconds, a mixture of 5 parts dimethyidichlorosilane (DMDCS) and onepart trichloromethylsilane is introduced into the reaction chamber for 5minutes. After an additional 30-second stabilization period, the gasesare exhausted from the chamber for 10 minutes, following which thesubstrate is removed from the chamber. FAS (B) is added and after 60-90seconds of treatment, the glass substrate is cleaned with N-butanol. Theinitial advancing contact angle is greater than 100° and greater than65° after 300 Taber Cycles.

Example XXIV (Invention)

[0083] A glass substrate is cleaned using the procedure in Example XVI.The substrate is placed into a carrier and is blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. Chamber humidity is adjusted to 14%, and thenheld at that humidity for 5 minutes. After a stabilization period of 30seconds, a trichloromethylsilane (TCMS) is introduced into the reactionchamber for 5 minutes to produce a surface layer having a surfaceroughness of from about 1 to 6 nm. RMS and a higher degree ofhydrophobicity as measured by contact angle than a surface derived frompurely SiCl₄. After an additional 30-second stabilization period, thegases are exhausted from the chamber for 10 minutes, following which thesubstrate is removed from the chamber. FAS (B) is added and after 60-90seconds, the glass substrate is cleaned with N-butanol. The initialadvancing contact angle is greater than 100° and greater than 65° after300 Taber Cycles.

Example XXV (Invention)

[0084] A glass substrate is cleaned using the procedure in Example XVI.The substrate is placed into a carrier and blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. After a period to ensure stabilization of thehumidity within the reaction chamber, about 30 seconds,trichloromethylsilane is introduced into the reaction chamber for about5 minutes to generate a first layer of an SiO_(x)Me_(y) layer having anRMS surface roughness of about 1 mμ and preferably less than about 6 mμ.The chamber is subsequently purged, and rehumidified to at least about14 percent. After a 30-second stabilization period,dimethyidichlorosilane (DMDCS- SiCl₂Me₂) and methyltrichlorosilane(MTCS-SiCl₃CH₃) are added in equimolar amounts to the chamber for atotal of 5 minutes. The reaction chamber humidity is adjusted to about14%, and then held at a relatively constant humidity for about 5 minutesto then generate a crosslinked layer. Optionally, after an additionalstabilization period of at least 30 seconds, methyltrichlorosilane(MTCS) is introduced into the reaction chamber for an additional fiveminutes to provide a capping layer. The reaction chamber is subsequentlyevacuated after a final coating is applied, and the coated substrate isremoved from the chamber. The initial advancing contact angle is greaterthan 70° and greater than 50° after 300 Taber Cycles.

Example XXVI (Invention)

[0085] A glass substrate is cleaned using the procedure in Example XVI.The substrate is placed into a carrier and blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. After a period to ensure stabilization of thehumidity within the reaction chamber, about 30 seconds,trichloromethylsilane is introduced into the reaction chamber for about5 minutes to generate a first layer of an SiO_(x)Me_(y) layer having anRMS surface roughness of about 1 mμ and preferably less than about 6 mμ.The chamber is subsequently purged, and rehumidified to at least about14 percent. After a 30-second stabilization period,dimethyldichlorosilane (DMDCS- SiCl₂Me₂) and Silicon Tetrachloride(SiCl₄) are added in to the chamber for a total of 5 minute. The amountof each reactant is about 1 to about 3 (e.g. 1 DMDCS to 3 SiCl₄)depending on the degree of durability or hydrophobicity or both desired.The reaction chamber humidity is adjusted to about 14%, and then held ata relatively constant humidity for about 5 minutes to then generate acrosslinked layer. The reaction chamber is subsequently evacuated aftera final coating is applied, and the coated substrate is removed from thechamber. The initial advancing contact angle is greater than 60° andgreater than 45° after 300 Taber Cycles.

Example XXVII (Invention)

[0086] A glass substrate is cleaned using the procedure in Example XVI.The substrate is placed into a carrier and blown dry using driedcompress air. The cleaned substrate is placed into the reaction chamberparallel to the gas flow. After a period to ensure stabilization of thehumidity within the reaction chamber, about 30 seconds,trichloromethylsilane is introduced into the reaction chamber for about5 minutes to generate a first layer of an SiO_(x)Me_(y) layer having anRMS surface roughness of about 1 nm and preferably less than about 6 nm.The chamber is subsequently purged, and rehumidified to at least about14 percent. After a 30-second stabilization period,dimethyidichlorosilane (DMDCS- SiCl₂Me₂) and Silicon Tetrachloride(SiCl₄) are added in to the chamber for a total of 5 minute. The amountof each reactant is about 5 parts to 1 part respectively (e.g. 5 DMDCSto 1 SiCl₄) depending on the degree of durability or hydrophobicity orboth desired. The reaction chamber humidity is adjusted to about 14%,and then held at a relatively constant humidity for about 5 minutes tothen generate a crosslinked layer. After an additional stabilizationperiod of at least 30 seconds, methyltrichlorosilane (DMDCS) isintroduced into the reaction chamber for an additional five minutes toprovide a capping layer. The reaction chamber is subsequently evacuated,and the coated substrate is removed from the chamber. The initialadvancing contact angle is greater than 100° and greater than 65° after300 Taber Cycles.

[0087] While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A substrate having a hydrophobic surface coatingcomprised of a silicon oxide anchor layer which exhibits a root meansquare surface roughness of less than about 6.0 nm.
 2. The substrate ofclaim 1, wherein the anchor layer exhibits a surface roughness of lessthan about 5.0 nm.
 3. The substrate of claim 1, wherein the anchor layerexhibits a surface roughness of greater than about 4.0 nm.
 4. Thesubstrate of claim 1, wherein the hydrophobic coating further comprisesthe humidified vapor-deposited reaction product of at least onealkylchlorosilane applied over the anchor layer.
 5. The substrate ofclaim 4, wherein the alkylchlorosilane is dimethyldichlorosilane ortrimethylchlorosilane.
 6. The substrate of claim 1, wherein thehydrophobic coating comprises a layer of a humidified vapor-depositedreaction product of dimethyidichlorosilane (DMDCS) on the silicon oxideanchor layer, and a layer of a humidified vapor-deposited reactionproduct of trimethylchlorosilane (TMCS) applied over the DMDCS layer. 7.The substrate of claim 1, wherein the hydrophobic coating comprises alayer of polydimethylsiloxane (PDMSO) chemically bound to said anchorlayer.
 8. The substrate of claim 1, wherein the hydrophobic coatingcomprises a layer of cross-linked polysiloxane chemically bound to saidanchor layer.
 9. The substrate of claim 8, wherein the hydrophobiccoating comprises at least one layer which is the humidifiedvapor-deposited reaction product of dimethyldichlorosilane (DMDCS) ortrimethylchlorosilane (TMCS) applied over the cross-linked polysiloxanelayer.
 10. A substrate having a hydrophobic surface coating comprised ofa silicon oxide anchor layer exhibiting a haze value of less than about3.0%.
 11. The substrate of claim 10, wherein the anchor layer exhibits ahaze value of less than about 2.0%.
 12. The substrate of claim 10,wherein the anchor layer exhibits a haze value of less than about 1.5%.13. A substrate which comprises a hydrophobic coating having an anchorlayer on a surface of the substrate comprised of a humidified reactionproduct of silicon tetrachloride vapor-deposited at a relative humidityof less than about 50%.
 14. The substrate of claim 13, wherein thesilicon tetrachloride is vapor-deposited at a relative humidity of lessthan about 45%.
 15. The substrate of claim 13, wherein the silicontetrachloride is vapor-deposited at a relative humidity of less thanabout 40%.
 16. The substrate of claim 13, wherein said hydrophobiccoating is comprised of the humidified reaction product of said silicontetrachloride and an alkylchlorosilane.
 17. The substrate of claim 16,wherein said alkylchlorosilane includes trimethylchlorosilane (TMCS).18. The substrate of claim 17, wherein said silicon tetrachloride andTMCS are vapor-deposited as a mixture.
 19. The substrate of claim 18,wherein said mixture contains a ratio of said silicon tetrachloride toTMCS of between about 4.0:.05 to about 4.0:1.5.
 20. The substrate ofclaim 18, wherein said mixture contains a ratio of said silicontetrachloride to TMCS of about 4.0:1.0.
 21. A substrate having ahydrophobic coating comprised of the reaction products of a chlorosilylgroup containing compound and a chloroalkylsilane.
 22. The substrate ofclaim 21, wherein said hydrophobic coating comprises an underlayer whichincludes said chlorosilyl group containing compound, and a capping layerover said underlayer which includes said chloroalkylsilane.
 23. Thesubstrate of claim 22, wherein said underlayer also includes a secondchloroalkylsilane different from said chloroalkylsilane in said cappinglayer.
 24. The substrate as in claim 21, wherein the underlayer includesthe humidified vapor deposition reaction product of silicontetrachloride.
 25. The substrate of claim 24, wherein the capping layerincludes at least one alkylsilane selected from the group consisting ofSiCl₂(CH₃)₂, CF₃(CF₂)₅(CH₂)2SiCl(CH₃)₂ and (CF₃)₂FC-O(CH₂)₃SiCl₂CH₃. 26.The substrate of claim 21, wherein the hydrophobic coating includes anunderlayer of cross-linked polydimethylsiloxane and a capping layer oversaid underlayer of the reaction product of a fluoroalkylsilane.
 27. Thesubstrate of claim 26, wherein said fluoroalkylsilane isCF₃(CF₂)₅(CH₂)2SiCl(CH₃)₂ or (CF₃)₂FC-O(CH₂)₃SiCl₂CH₃.
 28. The substrateof claim 21, having a tilt angle of about 35° or less, and a contactangle after 300 Taber abrasion cycles of greater than about 65°.
 29. Thesubstrate of claim 28, having a tilt angle of about 20° or less, and acontact angle after 300 Taber abrasion cycles of greater than about 70°.30. A glass substrate having a hydrophobic surface coating comprised ofan underlayer of cross-linked polysiloxane, and a capping layer which isthe reaction product of a fluoroalkylsilane, said surface coatingexhibiting a tilt angle (30 μL drop) of about 35° or less, and a contactangle of greater than about 65°.
 31. The glass substrate of claim 30,wherein the fluoroalkylsilane is CF₃(CF₂)₅(CH₂)2SiCl(CH₃)₂ or(CF₃)₂FC-O(CH₂)₃SiCl₂CH₃.
 32. A process for forming hydrophobic coatingson substrates comprising contacting a surface of the substrate to becoated with vapors of a chlorosilyl group containing compound, and analkylsilane in a humid room temperature atmosphere.
 33. The process ofclaim 32, wherein the vapor of the chlorosilyl group containing compoundand the vapor of the alkylsilane are brought sequentially into contactwith the substrate.
 34. The process of claim 33, wherein the chlorosilylgroup containing compound is silicon tetrachloride, and wherein thechloroalkylsilane is dimethyldichlorosilane (DMDCS).
 35. The process ofclaim 32, wherein the vapors of the chlorosilyl group containingcompound and the alkylsilane are brought into contact simultaneouslywith the substrate.
 36. The process of claim 30, wherein thechloroalkylsilane compound is silicon tetrachloride, and wherein thechloroalkylsilane is dimethyidichlorosilane (DMDCS) ortrimethylchlorosilane (TMCS).
 37. The process of claim 36, where thechloroalkylsilane comprises DMDCS and wherein a weight ratio of silicontetrachloride to DMDCS is from about 1:1 to 1:30.
 38. The process ofclaim 37, wherein the weight ratio is from about 1:5 to about 1:15. 39.The process of claim 36, wherein the chloroalkylsilane comprises TMCSand wherein weight ratio of silicon tetrachloride to TMCS is from about4.0:0.5 to about 4.0:1.5.
 40. The process of claim 39, wherein theweight ratio is about 4.0:1.0.
 41. The process of claim 32, whichfurther comprises applying a capping layer onto the substrate bycontacting the substrate with a fluoroalkylsilane (FAS).
 42. The processof claim 41, wherein the FAS is applied as a liquid over the vapordeposited coating.
 43. The process of claim 42, wherein the FAS isCF₃(CF₂)₅(CH₂)2SiCl(CH₃)₂ or (CF₃)₂FC-O(CH₂)₃SiCl₂CH₃.
 44. A process forforming a hydrophobic coating on a glass substrate comprising: (a)contacting a surface of the glass substrate to be coated with a silicontetrachloride vapor for a time sufficient to form a silicon oxide layeron the surface of the glass substrate; and then (b) simultaneouslycontacting the silicon oxide layer with vapors of silicon tetrachlorideand dimethyldichlorosilane (DMDCS) for a time sufficient to form across-linked layer of polydimethylsiloxane (PDMSO).
 45. The process ofclaim 44, which further comprises (c) subsequently applying afluoroalkylsilane (FAS) capping layer over said cross-linked layer ofPDMSO layer.
 46. The process of claim 44, wherein the weight ratio ofsilicon tetrachloride to DMDCS is from about 1:1 to about 5:1.
 47. Theprocess of claim 46, wherein the weight ratio is from about 3:1 to about4:1.
 48. The process of claim 45, wherein the FAS is applied as a liquidover the PDMSO layer.
 49. The process of claim 48, wherein the FAS isCF₃(CF₂)₅(CH₂)2SiCl(CH₃)₂ or (CF₃)₂FC-O(CH₂)₃SiCl₂CH₃.
 50. A process forforming a hydrophobic coating on a glass substrate comprisingsimultaneously contacting the glass substrate with vapors of silicontetrachloride and trimethylchlorosilane (TMCS) for a time sufficient toform a hydrophobic coating thereon.
 51. The process of claim 50, whichfurther comprises subsequently applying a capping layer.
 52. The processof claim 50, wherein the weight ratio of silicon tetrachloride to TMCSis from about 4.0:0.5 to about 4.0:1.5.
 53. The process of claim 52,wherein the weight ratio is about 4.0:1.0.
 54. The process of claim 50,which comprises forming a liquid mixture of liquid silicon tetrachlorideand TMCS, and depositing a vapor of the mixture onto the substrate. 55.A coated glass substrate made by the process of claim
 44. 56. Thesubstrate of claim 4, wherein the alkylchlorosilanes comprisedimethyldichlorosilane and methyltrichlorosilane.
 57. The substrate ofclaim 4, wherein the alkylchlorosilanes are dimethyidichlorosilane andmethyltrichlorosilane and are added in equimolar amounts.
 58. Thesubstrate of claim 56 wherein the ratios of dimethyidichlorosilane andmethyltrichlorosilane are in the range of from 5 part to 1 part to about1 part to 3 part respectively by weight.
 59. The substrate of claim 56wherein the alkyl chlorosilane layer is capped withmethyltrichlorosilane.
 60. The substrate of claim 56 wherein the alkylchlorosilane layer is capped with a fluoroalkylsilaneFAS(B).
 61. Thesubstrate of claim 1 wherein the hydrophobic coating comprises a layerof a humidified vapor-deposited reaction product ofdimethyidichlorosilane and methyltrichlorosilane on the silicon oxideanchor layer, and a capping layer of a humidified vapor-depositedreaction product of trimethyl chlorosilane applied over the DMDCS andTMCS layer.
 62. The substrate of claim 4 wherein the alkylchlorosilanesare dimethyidichlorosilane, methyltrichlorosilane, and silicontetrachloride added to the reaction chamber in equimolar amounts. 63.The substrate of claim 62 wherein the FAS(B) is added as a cappinglayer.
 64. A substrate having a hydrophobic surface coating comprised ofa hybridized organo-silicon oxide anchor layer, SiO_(x)R_(y) wherein yis at least one and is an organic group having 6 or less carbons and xis at least one, the substrate having a root mean square surfaceroughness of less than about 6.0 nm.
 65. The substrate of claim 64wherein the anchor layer exhibits a surface roughness of less than about5.0 nm.
 66. The substrate of claim 64 wherein the anchor layer exhibitsa surface roughness of greater than about 4.0 nm.
 67. The substrate ofclaim 64 wherein the hydrophobic surface coating further comprises atleast one humidified vapor-deposition reaction product of at least onealkylchlorosilane, chlorosilane, or both applied over the anchor layer.68. The substrate of claim 64 wherein the hybridized organo-siliconoxide anchor layer is derived from vapor depositedtrichloromethylsilane.
 69. The substrate of claim 67 wherein the silanesare dimethyidichlorosilane and silicon tetrachloride.
 70. The substrateof claim 64, further comprising a capping layer of FAS(B),methyltrichlorosilane, or both.